Finally , it ends over the week-end ! (It has to you know ! ) . . . Every one flies back, only to come back next year to ponder “almost the same issue” all over again. (Some times the questions are left unanswered for decades ! Not getting an answer is okay , after all research is a journey towards truth but sustaining a confusion or creating new one has been a norm in recent times.)

*Sorry , If am provocative , I need to be genuine in my expression.

Coming to the topic, Aspirin is one wonder drug which made a big impact on CAD risk . We know there is something great with this cheapest and humble Dual COX blocker.The only weak point is ,it lacks the glamor quotient like that of newer antiplatelets, NOACs and their clones.

Its my perception ,big breaking research has tried to ditch this drug for quiet a while .But ,it was all too difficult to go for the kill.So these studies circumnavigate the real issue. and end up with suspicious conclusions (or Inconclusions !) always trying to hide behind sinister statistics of course with a questionable caveat !

What’s new in the topic of Primary prevention of CAD ?

Two major studies were released recently in August 2018

Both studies suggest caution for Aspirin. If Aspirin is really bad it would (and should) have buried long ago. We should be thankful even in these testing times for truth ,this humble drug is fighting back and forth .(Digoxin is another close cousin of Aspirin fighting for the existence crisis in cardiology ! )

So what is the role of Aspirin in primary prevention of CAD ?

This question doesn’t make sense in many clinical situations.

Primary and secondary prevention are defined with reference to manifest vascular event. We will not know how much of silent CAD exist in asymptomatic persons.Primary prevention of CAD itself could be a misnomer as most elderly do carry at-least some form of CVD. For example, If a patient with manifest peripheral arterial disease (PAD) and takes Aspirin , its secondary prevention for PAD but becomes primary prevention for CAD . . . isn’t ?

Final message

We know Aspirin continues to be the flag bearer of all DAPT regimen.I wish it remains a star in primary prevention as well. It looks like(for me) these studies are another attempt to pull down Aspirin in primary prevention .I think ARRIVE failed to reach the desired conclusion. Aspirin is a warrior and it will never allow that to happen and ASCEND to glory again !

Postamble

Modern drug research appears to pursue a study till the desired conclusion is reached. We need important drugs in many vital areas of cardiology .Our energy should be focused to find new molecules. It is worrying trend(if its true !) if efforts are wasted to finish off humble generic drugs with proven worthiness. Doing research in established concepts is the most silly thing to do. Its duplication of knowledge.

Counterpoint

It’s scientific blasphemy to criticise studies without analysing it in a professional manner.It appears all too brutal to take a biased view and questioning the motive of researchers. Yes agreed , I may be prejudiced , . . but , why a doctor of this caliber make a statement of this sort ?

Its a fact , there are so many true scientist doing their job right, my query is simple why we are not getting clear answer in many common issues In spite of great research ?

Is it the limitation of science or vagaries of research ? I think it’s more of a Intellectual insufficiency aided by malfunctioning regulators !

Aspirin for primary prevention of CVD is an ongoing controversy for more than 2 decades. Please note, the controversy is not in the competence of Aspirin to prevent cardiovascular event, but in the potential risk of GI bleed and whether that risk is worth taking. Secondary prevention has no such issues as the benefits easily outweigh the potential bleeding risk .

Male vs female

There is a “gender” and “age” difference in the ability of Aspirin to prevent vascular events.Aspirin primarily prevents MI in men(>45) and stroke in women(>55) (Funny it may look, that’s what data says!)

Age

Hence, the target age group for aspirin is between 45/55 to 80 years. (Up to 45 and beyond 80 it has no role .Beyond 80 , risk of hemorrhagic stroke is significant )

Diabetic vs non diabetic

Many believe all diabetics should straightway get Aspirin as it was considered CAD equivalent.Its not acceptable to all. . American diabetic association has risk stratified DM and advice Aspirin only in high / Intermediate risk.Look for Key word ie “Net benefit“ (Ref 2)

Why so much confusion ? and What can be the conclusion ?

The confusion is because each scientific body like AHA, ESC, ACCP, ADA ,USPSTF have their own inference and the presence of too many risk assessment tools adds further dizziness .(SCORE /FRAMINGHAM, etc). It tempts me to say ignore all these and use cortical sense !

Fortunately ,we do have some clarity as there is a common theme in all these advisories .Aspirin is indeed a wonder drug and able to block the platelets to prevent acute thrombus formation in the critical circulations.(FDA doesn’t seem to agree with this , How can a cheap generic do that job so effectively ? Let the Bayer fight ! )

It seems reasonable to conclude

All men and women between 45/55 to 80 years should get Aspirin (81mg /day or 325mg alternate days ) if there is at least one or two CVD risk factors provided there is no major bleeding risk .

Ongoing studies on primary prevention with Aspirin

ASCEND: A Study of Cardiovascular Events in Diabetes; or with diabetes taking a statin

ENVIS-ion (Aspirin for the Prevention of Cognitive Decline in the Elderly )

ASPREE (Aspirin in Reducing Events in the Elderly)

These studies are expected to bring more data (and be ready for more confusion!)

Can we use Clopidogrel for primary prevention if a person is intolerant to Aspirin ?

Logic may say yes.As of now it can not be advised for primary prevention.

We essentially live in our blood vessels and age in our arteries.CAD is the principal cardio vascular disease, which God has created in Homo-sapiens to ensure they do not stay more than “allotted life span” in this planet. Of course , the current generation cardiologists equipped with scientific weapons , have since decided to take the fight directly in the Almighty’s domain .Contrary to the popular medical doctrine, treating an established CAD seems to be easier task than preventing a new onset CAD.

While , arteriosclerosis is a normal aging process, atherosclerosis could be an aging as well as a distinctive pathological process. However , athero-thrombosis is a definite pathology of vessel wall .We know at any time atherosclerosis can transform into athero-thrombosis and result in clinical event depending upon the triggers and other associated conditions, which we refer to as major or minor risk factors.

Secondary prevention is prevention of second or subsequent episodes following the first clinical event.(*What if , if the first event is silent and never known ? )

For all practical purposes CAD and coronary atherosclerosis is synonymous. Can we prevent atherosclerosis in human biological system ? What are we supposed to refer to such a preventive measure , if any ?

We are biased towards obstructive CAD as we often think it is the the only form of CAD .Then , how do we diagnose , treat and prevent a minimal non flow limiting plaque , coronary endothelial dysfunction , or acute coronary erosion that can occur in very early stages of atherosclerosis, in other wise healthy persons.(Routine IVUS ,OCT ? Futile isn’t )

Preventing a CAD in a patient with peripheral vascular disease or preventing CAD in a patient with TIA or stroke is secondary prevention for cerebrovascular disease but falls within the definition of primary prevention of CAD.

Then comes the new semantics :Primordial prevention .This could be same as primary (or another version of primary prevention ).Primordial prevention is preventing development the risk factor itself (Like DM,HT, Dyslipidemia )

So ,whenever , we talk about primary prevention of CAD by Aspirin or Statins ,realize the complexities involved .Before i finish, let me make you dizzy further with this quixotic one . In a multivessel CAD, as the atherosclerotic plaques are scattered across the coronary arteries in various stages of maturity , long term Aspirin following anterior STEMI has to secondary prevent an event in LAD territory . . . but primary prevent a plaque disruption in RCA territory !